1,476 research outputs found
Mercury chloride-induced oxidative stress in human erythrocytes and the effect of vitamins C and E in vitro
Mercury can exist in the environment as metal, as monovalent and divalent salts and as organomercurials, one of the most important of which is mercuric chloride (HgCl2). It has been shown to induce oxidative stress in erythrocytes through the generation of free radicals and alteration of thecellular antioxidant defense system. The effect of simultaneous pretreatment with vitamins C and E on the toxicity of HgCl2 in human erythrocytes was evaluated. We examined the effect of several differentdoses of HgCl2 (1.052, 5.262, 10.524 M), or HgCl2 in combination with vitamin C (VC; 10 M) and vitamin E (VE; 30 M), on the levels of malondialdehyde (MDA) and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in human erythrocytes in vitro. Erythrocytes were incubated under various treatment conditions (HgCl2 alone, vitamins alone, or HgCl2 plus vitamin) at 37°C for 60 min and the levels of MDA and SOD, CAT and GPx activities, were determined. Treatment with HgCl2 alone increased the levels of MDA and decreased SOD, CAT and GPx activities in erythrocytes (P < 0.05). VC and VE-pretreated erythrocytes showed a significant protection aganist thecytotoxic effects induced by HgCl2 on the studied parameters. There were no statistical differences among VC+VE-treated erythrocytes, as compared to non-treated control cells. These results indicated that the presence of vitamins at concentrations that are similar to the levels found in plasma could be able to ameliorate HgCl2-induced oxidative stress by decreasing lipid peroxidation and altering antioxidant defense system in erythrocytes
The viscosity and thrombocytic-aggregation disorders in patients, suffering myocardial infarction with the ST segment elevation
Objective. Analysis of changes in viscosity and disorders of the thrombocytes-aggregation process under impact of various tactical, diagnostic and intervention approaches in patients, suffering myocardial infarction with persistent elevation of ST segment in presence of multivascular affection of coronary arteries.
Materials and methods. In the investigation four tactical and treatment-diagnostic approaches were used through year of observation.
Results. In patients, suffering myocardial infarction and persistent elevation of ST segment the hyperviscosity and hypercoagulation syndromes were revealed, which have manifested in first weeks by compensatory growth of thrombocytes quantity, the blood viscosity, level of fibrinogen and aggregation properties of thrombocytes. Conduction of additional more profound examination of coronary blood circulation and further application of postponed stenting of the infarction-dependent arteries have promoted lesser amplitude of fluctuations of all laboratory indices, than in other tactical and treatment approaches.
Conclusion. Standard tactical and treatment-diagnostic principles in management of such category of patients do not permit to improve the state of the viscosity and coagulation-aggregation parameters principally, even while application of double antiaggregation therapy
Screening in a new modified gravity model
We study a new model of Energy-Momentum Squared Gravity (EMSG), called
Energy-Momentum Log Gravity (EMLG), constructed by the addition of the term
, envisaged
as a correction, to the Einstein-Hilbert action with cosmological constant
. The choice of this modification is made as a specific way of
including new terms in the right-hand side of the Einstein field equations,
resulting in constant effective inertial mass density and, importantly, leading
to an explicit exact solution of the matter energy density in terms of
redshift. We look for viable cosmologies, in particular, an extension of the
standard CDM model. EMLG provides an effective dynamical dark energy
passing below zero at large redshifts, accommodating a mechanism for screening
in this region, in line with suggestions for alleviating some of the
tensions that arise between observational data sets within the standard
CDM model. We present a detailed theoretical investigation of the
model and then constrain the free parameter , a normalisation of
, using the latest observational data. The data does not rule out the
CDM limit of our model (), but prefers slightly negative
values of the EMLG model parameter (), which leads to
the screening of . We also discuss how EMLG relaxes the persistent
tension that appears in the measurements of within the standard
CDM model.Comment: 17 pages, 11 figures, 1 table; matches the version published in EPJ
Molecular diagnosis to identify new sources of resistance to sclerotinia blight in groundnut (Arachis hypogaea L.)
Sclerotinia blight, caused by soil-borne fungus Sclerotinia minor Jagger, is one of the destructive diseases in groundnut. Pathogen affected plants usually displays lesions, wilt and collapse which cause high yield losses. Traditional field screening is time and resources consuming. Molecular markers associated with resistance genes offer an alternative selection technique which is relatively easy, more definite and not influenced by environmental fluctuations. In the present investigation, a marker-assisted diagnosis was done to screen 256 diverse germplasm for the presence or absence of SSR markers reported resistance or susceptibility to sclerotinia blight. One hundred and forty two genotypes from different botanical varieties were recognized as new potential sources of resistance to sclerotinia blight for field evaluation. The banding pattern related to the disease resistance is observed at high frequency in the variety vulgaris (39.4 %) and less distributed in the varieties fastigiata (38.0 %) and hypogaea (19.7 %) among the resistant genotypes in the collection. These genotypes had same banding pattern as reported for resistance germplasm. This work reports the successful application of marker-assisted diagnosis as a tool to identify resistance to sclerotinia blight in diverse collections
Identification of rust resistance in groundnut using a validated SSR marker
Groundnut (Arachis hypogaea L.) is an important crop cultivated in over 100 countries in the world. The rust disease of groundnut, caused by Puccinia arachidis Speg., can cause significant yield losses in tropical and subtropical areas. The disease affects not only seed yield but also fodder yield and quality. There are chemicals available to control rust; however, the development of resistant varieties is the most reasonable way to improve yield and quality, and to reduce the adverse effects of chemicals on the ecosystem. Characterization of germplasm diversity to identify resistant sources using traditional methods is a lengthy process and requires laborious field testing. Molecular marker-aided selection offers an alternative breeding method that is relatively easy, precise, and not affected by environmental fluctuation. In the present study, a validated SSR marker, GM1954, linked to the rust disease resistance gene was used for 256 groundnut genotypes to select rust resistance. This study reports the successful application of marker-assisted selection for further rust-resistant breeding programs in groundnut. Molecular analyses revealed that the banding pattern related to disease resistance was observed at high frequency in the variety hypogaea among the nine identified resistant genotypes in the collection. Approximately 3 % of the collection was selected for further field, greenhouse, and hybridization experiments
Validation of field resistance to late leaf spot by using a molecular marker in groundnut
Groundnut or peanut (Arachis hypogaea L.) is an important oilseed crop which is
valued as a rich source of high quality edible oil, protein, minerals and vitamins. It
offers nutritional and economic benefits to the consumers and farmers, respectively.
However there are many biotic and abiotic constraints to groundnut production in various
eco-agricultural systems. The late leaf spot (LLS) is one of the most widespread
and damaging foliar diseases of groundnut and it can reduce pod and fodder yields
to an extent of over 50%, also affects adversely quality of seeds. Much of the global
groundnut breeding efforts therefore have been directed to develop cultivars with high
yields and also incorporating genes conferring resistance or tolerance to LLS disease.
Integration of molecular marker aided selection with field based breeding is important
to enhance the precision and speed of developing peanut cultivars with LLS resistance.
In this perspective, many LLS resistance-related molecular markers have been
developed to aid in the selection processes. The SSR marker, PM 384, is one of these
markers and showed significant association with LLS resistance (Shoba et al. 2012,
Euphytica, 188:265-272). The groundnut collection including 39 genotypes was employed
for validating LLS resistance-linked marker (PM 384) and identifying resistant
individuals. These genotypes were evaluated in the field with nine point disease
scale to screen the genotypes for sources of resistance to LLS. Plants with a disease
score of 1-3 and 6-9 were designated as being resistant and susceptible, respectively.
After field evaluation, field scored genotypes were validated by LLS resistance using
the linked marker, PM 384
Wall-Resolved Large Eddy Simulations of Transonic Shock-Induced Flow Separation
This paper reports the wall-resolved large eddy simulations of shock-induced boundary layer separation over an axisymmetric bump for a flow Mach number of 0.875 and a chord-based Reynolds number of 2.763 million. The incoming boundary layer has a momentum-thickness Reynolds number of 6600 at one and a half chord lengths upstream of the leading edge. The calculations simulate the experiment by Bachalo and Johnson (AIAA Journal, Vol. 24, No. 3, 1986), except that the tunnel walls are ignored and the simulations are performed assuming free air with as many as 24 billion grid points. The effects of domain span, grid resolution and time step on the predictions are examined. The results are found to show some sensitivity to the studied parameters. Owing to the outer boundary conditions, the predicted surface pressure distribution as well as the flow separation and reattachment locations tend to agree better with the experimental results from the larger (6 6 ft) tunnel than those from the smaller (2 2 ft) tunnel. The predicted Reynolds shear stress profiles in the separated region differ by as much as 31%from the experimental results that were only obtained in the smaller tunnel. The most accurate surface pressure distribution obtained in this study lies within the scatter of the measurements taken in the two facilities
- …